rainfall influence on lizard activity patterns in a piñon-juniper woodland vivien enriquez
DESCRIPTION
Rainfall Influence on Lizard Activity Patterns in a Piñon-Juniper Woodland Vivien Enriquez Beloit College Summer 2013. Introduction. Focal species 1) Chihuahuan Spotted Whiptail (Aspidoscelis exsanguis) 2) New Mexico Whiptail (Aspidoscelis neomexicana) Natural History - PowerPoint PPT PresentationTRANSCRIPT
Rainfall Influence on Lizard Activity Patterns in a Piñon-
Juniper Woodland
Vivien Enriquez Beloit College Summer 2013
Introduction
Focal species
1) Chihuahuan Spotted Whiptail (Aspidoscelis exsanguis)2) New Mexico Whiptail (Aspidoscelis neomexicana)
Natural History
1) Native to the North American southwest 2) All female species 3) Active foragers 4) Active in the early morning and late afternoon
Aspidoscelis exsanguis
Aspidoscelis neomexicana
Introduction
• Sensitive to changes in habitat structure and function
• Altered whiptail abundance in response to climate change/drought stress
2011 Precipitation and lizard abundance
May 27th-August 9th
Introduction
Red = rainfall plotsGreen = drought plots Blue = weekly precipitation
Grah: Ryan, 2011
Introduction
• Rainfall pulses impact lizard abundance and activity
• Using this data to form new questions about what drives lizard behavior
• Using activity time budgets to illustrate daily behavior and habitat use
Introduction
Questions:
1) How does long term artificial drought and rainfall addition influence lizard behavior and habitat use?
MethodsResearch took place at the Sevilleta National Wildlife Refuge
New Mexico
Rainfall Manipulation Experiment, Piñon-Juniper Woodland, Los Piños Mountains
Methods
Treatment 6 Total
Drought 11 observations
Rainfall 11 observations
Methods
30 minute surveys per plot, 2 times a week
• Start at 8:30 a.m.
• Drought and rainfall treatment plots are surveyed at every visit.
• Various plots are substituted for others throughout the week.
Behavioral observation and recording: 12 minute observational period, 22 individuals
• Videos recorded and then analyzed
• Individual behaviors timed (in seconds) and categorized
• Behaviors and habitats organized in a template
• Activity time budget calculated
Methods
Behavior & Habitat Codes:
BA - basking OH - open habitat
AF - active foraging SH - shaded habitat
o searchingo diggingo scratching
WA - walking
PC - prey capture
CL - climbing
Methods
Lizard ID: 0913.ASPEXS.PJ6.22
Activity Time Budgets: a measurement of time spent on each behavior.
• Total time of each activity divided by the total amount of time spent observing (in seconds), then multiplied by 100.
Methods
Behavior AF AF BA BA CL In Plot Out Plot
Habitat OH SH OH SH OH AF AF
Time (s) 20 5 40 65
Drought:
Rainfall:
ResultsBasking
Active foraging
ResultsDrought Treatments
ID: 0836.ASPEXS.PJ1.6
AF (SH) AF (OH) BA (OH) BA (SH) WA (OH) PC (OH)
6.9% 48.06% 24.24% 11.58% 8.3% .71%
AF (OH)
AF (SH)
BA (OH)
BA (SH)
WA (OH)
PC (OH)
Results Rainfall Plots
0936.ASPEXS.PJ4.8
AF (SH)
AF (OH)
BA (SH)
WA (OH)
WA (SH)
PC (SH)
AF (SH) AF (OH) BA (SH) WA (OH) WA (SH) PC (SH)
44.8% 14.44% 20.34% 2.9% 8.6% 8.6%
Results Active-Foraging by Treatment (Aspidoscelis exsanguis)
Active-Foraging in shade Active-Foraging in open habitat
Kruskal-Wallis TestChi-Square 8.9219
Chi-Square 1.6694DF 1
DF 1Prob>Chisq 0.0028 Prob>Chisq 0.1963
Results Basking by Treatment (Aspidoscelis exsanguis)
Basking in shade Basking in open habitat
Kruskal-Wallis TestChi-Square 2.9413
Chi-Square 1.2172DF 1
DF 1Prob>Chisq 0.0863 Prob>Chisq 0.2699
Discussion
Question: How does long term artificial drought and rainfall addition influence lizard behavior and habitat use?o Affects the amount of time lizards spend
performing certain behaviors in the shade vs. open habitat
o Promotes different common behaviors depending on which treatment the lizard is located in
Discussion• Future directions: project replication after rainfall
manipulation experiment ends.
- Other factors: vegetation cover/health, soil quality, prey abundance
1) Will we see similar results?
2) If drought landscape recovers, will lizard behavior adapt?
Acknowledgements
I would like to thank: Mentor - Mason Ryan
Elizabeth GallagherREU Program - Amaris Swann and
studentsSevilleta National Wildlife Refuge
Questions?